Coffee brewer



Nov. 25, 1941. H. F. KoRs COFFEE BREWER Filed Aug. 1v. 1939 enameled. if desired.

`Patented Nov. 25, 1941 'UNITED STATES" PATENT orner-:- Y2.26.'.,ss1

COFFEE Henry F. Kors, Chicagmlll., assigner 'to Korwood Incorporated, Chicago, lli., a corporation of Anniiention Annet 11, 193s, serial No. acusa 9Claims.

This invention relates to an improved coffee brewer, and is concerned in particular with improvements in the double-boiler type disclosed in elevation above the layer of coiee grounds tov cause air to be drawn upwardly therethrough to relieve the vacuum during the ltering operation quickly enough so as not to impede the operation.

The invention is illustrated in the accompanying drawing, in which- Fig. 1 is a central vertical section through a coffee brewer made in accordance with my invention, the inner bowl being shown in full. lines in inverted ltering position and in dotted lines in brewing position;

Fig. 2 is a face view of the ltering head taken on the line l2-2 of Fig. 1;

Fig. 3 is a developed sectional detail on the arcuate line 3-3 of Fig. 2;

Fig. 4 is a` fragmentary view illustrating partly in side elevation and partly in section the appli- (ci. sans) ports the bowl in the brewing position, indicated" tien n thereof and cernes n handle is. onev ni the beads Il serves as al means forsupportingthe inner bowl D upon Vthe rim. of -'the outer bowl inthe inverted filtering position illustrated v in lull lines, and the other bead similarly supe' in dotted lines. A lid or .cover 20. -which is preferably made of glass'tofmatch the. bowls 9 and il, has an annular downwardly projecting iiange 2i oi.' a diameter to nt over the outside oi'y the rim'll oi the inner bowl l and inside the rim i! of the outer bowl I6, as illustrated in Figs. 5 and .y 6, respectively. AThere are outwardly projectingA lugs 22 rormedon the rim Il :of the inner bowl 8 in uniformly circumterentially'spaced relation 'tol cooperate with inwardly projecting lugs 23 formed on the rim 24 of the sheet metal'filter head 25 that is adapted to be applied overthe. outside of the rim II of the inner bowl 9 in the manner illustrated in Figs. 1 and 4.. The ilange 2l on the lid 20 is therefore cut away, as indication of the mter head and alter doth antoine rim of the inner bowl:

, Figs. 5 and 6 are fragmentary views illustrating the way in which the specially `constructed lid fits on the outside of the rim of thel inner bowl and inside the rim of the'outer'bowl, and

Fig. 'l is a face view of a portion of a iilter head like that shown in Fig. v2 but having the spokes of the spider portion thereof ilanged. as indicated in the sectional detail Fig. 8, which is taken on the line 8-8 of Fig. '1. l

Similar reference numeralsare applied to corresponding parts throughout the views.

Referring to Fig. l, the reference numerals 9 and I0 designate the inner and outer bowls of the double-boiler type codee brewer ci my invention. Both are preferably made of glass, although either or both may, of course, be made of aluminum or other material and porcelain il is a pouring lip or spout provided on the outer bowl l0 so 'that it may be used as the coffee serverl in addition to being the boiler. A handle i2 is suitably secured to the bowl I0 by a metal band I3 which iits bef tween the annular beads It -formed onthe rim I5 of the bowl. Another band I6 is similarly mounted on the beaded portion l'i o! the inner bowl 8 in spaced relation to the reduced rim porcated at 28, to accommodate the lugs 22 when the lid 20 is placed on the .rim I8 or the inner bowl 9, as' illustrated in Fig. 5. v The lid2|l will be used on the inner bowl usually' only when cause when it is being used a's a coiee brewer. it. l r y is customary to 4have theiilter head 2li applied to the rim il, clamping a lter cloth 2l in place thereon, a'sv shown in Fig. 4, so that after the coilee is brewed andis'ready to be filtered, the

iilter head is in readiness for the iiltering operation. 'I'he lid 2l, in so far as the use of the dcvice as a coie'e brewer is concerned, will ordi-.- narily be used only on the outer bowl I0 when the latter is being used as a coffee server. The

and I8, asshown at 28 in Figs. 1 and 4, and will ange 2| on the -lid 26 may, if desired,'be used to close the pouring: spout Il, the lid. being turned to bring one of the out away portions into register with thespout only when pouring'` the rim I8 so that the marginal portion o! the iilter cloth '21 can be entered between the rims.

cause the filter head 26 to' fit snugly on therim i8 even beforethe head 25 is turned in the direction or the arrow ze shown in Fig. 4 in bring the lugs 23 into position under the lugs 22 and by wedging engagement therewith llock the lter head securely in place. Obviously the marginal portion 28 ci the lter cloth 21 in this operation will be gripped between the lugs-22' and 23, and inthat way the filter head is'still more securely held in place, there being no likelihood of the lugs 2,3'

backing oil the lugs 22 even when, as in actual practice, the iilterhead is turned with very vlittle iorce toward the 'locked position shown in Fig.v4. The iilter cloth, in other words. frictionally reu di the alter head 2s is e tride larger A in inside diameter than the outside diameter of sists. turning of theillter head 25 and hence it is only important to get theblugs 23. in position under the lugs 22 to prevent axial displacement of the filter head 25 oi! the rim l5. When the filter head 25 is applied in this manner with the filter cloth' l21 dry, there wil-l be no difiicultylater in turning the iilter head in the opposite direc tion to remove it after the coiee has been filtered. The illter head is of open spider construction with radial spokes 30 in the spider portion 3| dening large segmental-shaped openings 32 therebetween where large areas of the illter c loth 21willbe exposed to expedite filtering. If desired, I may provide a illter head like that shown at` 25' in Fig. '7 with spokes l lhaving outwardly projecting longitudinal flanges 23 provided on the edges'thereof. With such a construction, one can readily interfere with the mier cmth 21 mung snugly lagainst the inner surface of the filter head.

The lter cloth 21 has a center hole 34 through which an elongated tapered inspirator tube or nozzle is arranged to be entered with atight ilt,as indicated in 1. This tubeis entered in a center hole in theE central portion I of the spider portion 3i of th'e illter head and is suitably secured in place in said hole as by swedging. the tube being drawn from sheet metal, as indicated by its thin walls and being therefore adapt` ed for such assembling. The small end of the tube has a restricted air inlet orifice 21 provided therein. The cen/tral portion 25 of the spider 3l is offset in relation to the outer marginal portion 3l next to the rim 24, as clearly appears in Fig. 1,

-to'relieve the vacuum.A The flltercloth 21 in the illt'ering operation bulges downwardly through exert pressure laterally against the spokes of the to suit the taste.j brewing process, the

liquid in the inner bowl never reaches scaldlns y temperature, and I have found that a mellow flavored coffee is obtained free of any acrid taste so frequently-'.foundin codec made in other ways. The filter head {25g-and illter cloth 2'1 will be applied -to the inner bowl usually before the coffee is brewed, so that as soon as the coffee is prepared, the inner bowl 9 can be removed by means oi the handle Il and the water can be poured out from .the outer bowl I0, using the handle l2. Then the inner bowl is inverted over the outer bowl, resting with its beaded rim portion iltting in the rim portionof the outer bowl, as shown in full lines in Fig. 1. The filtered coifee drops from the filter head 25 into the bowl I0. as indicated at 42, while airis admitted between the rims of the bowls, as indicated at 43, to pass upwardly through the inspirator tube 35 and bubble through th'e unilltered coiIee, as indicated at 4I. 'I'he acceleration of filtering resulting from the openwork construction of the illter head 25 and the free inlet oi. air through the inspirator tube 35 to relieve vacuum above the uniiltered cotiee in the inner bowl l both are responsible for shortening the illtering time. When all of the` l coifee has been illtered, the inner bowl 9 is removed and the lid 20 is placed on the bowl Il and the latter then is used as the coffee server.

The outer bowl I0 is hot when the coffee is illtered into it, which. is obviously advantageous because the coffee can then be served piping hot. as many prefer it. I have found that the orifice 31 must be' restricted so that it bears a certain relationship to the combined filtering area of the openings 32. otherwise col'fee will ilow downwardly through the tube 35 instead of air ilowing upwardly therethrough. The elevation of the orifice 31 in relation tothe openings 22 is also important. apparently because the air will bubble through lthe unfiltered coilee only if the path from the orifice I1 to the level 40 is suillclently shorter than any other possible pathof air travel through the filter head. The air is, of course, drawn upwardly through the unfiltered coilee by reason of the reduction in pressure created above the liquid level as the liquid illters through the illter head.

In conclusion, it should be understood that I do not limit myself to the use of the illter lcloth 21 because I have found that a ilne mesh Monel metal gauge is satisfactory for the illtering metheopenings 32 under the weight of the conce grounds'and the unfiltered coilee above, as illustrated in Fig. 3, and the coffee drops from the cloth 21 mainly at the middle of these bulged por tions.' that is, along the lines a-a, b-b, cc, and

aL-d of Fig. 2. Incidentally, this sagging of the iilter cloth 21 between the spokes 30 further in- It is believed the foregoing description conveys y a good understanding of the objects and advan- -tages of my invention. The appended claims have been drawn with a view to covering all legitimate modifications and adaptations.

sures keeping the upper level I9 of the coffee grounds below the orifice end 31 of the tube 35,

so that there will be no interference with the inlet of air.

In operation, the inner bowl 9, containing ground' coffee-and the appropriategamount of,

water, is placed in the outer bowl I0, as shown in dotted lines in Fig. 1, after enough water has been put in' Dthe cuter bowl to boil without danser or overowing. This double-boiler then --brews the coffee in the inner bowl 9. and it takes fromeight to 'ten minutes to produce fairly strong coffee. The brewing time will be varied I claim: 1. The combination with an outer bowl having a rim portion, and an inner bowl adapted to be supported on the rim portion of the outer bowl gether denne enlarged segmental-shaped iilter openings between the substantially radial spokes thereof. a sheet of'iiltering material covering said filter openings and clamped about its marginal edge portion between the rim portion of the filter bowl and having a small air inlet orice provided f in the inner end thereof, the nozzle projecting into said inner bowl a distance which represents a small fraction of the depth of the bowl. and

said orifice beingtoo small for passage of liquid downwardly therethrough in the inverted filtering position ofthe second bowl but large enough for passage of air upwardly therethrough to relieve vacuum in the inner bowl above the level of liquid therein. Y

2. The combination with an outer bowl having a rim portion, and an inner bowl adapted to be supported on the rim portion of the outer bowl and also having a rim portion, of a filter head having a rim portion detachably secured to the rim portion of the inner bowl and also having a spider portion within the rim portion which together define enlarged segmental-shaped filter openings between the substantially radial spokes thereof, a sheet of filtering material covering saidfilter openings and clamped about its marginal edge portion between the rim portion of the filter head and the rim portion of the inner bowl, said Y spider portion having its spokes inclined to oset l the central portion thereof relative to the rim portion a predetermined distance into the inner bowl, and an air inspirator nozzle carried on the central portion of said spider and projecting therefrom through an opening in the sheet of ltering material into the inner bowl to a predetermined level therein and having a restrictedair inlet orice provided in the inner end thereof.

3. The combination with an outer bowl having a rim portion, and an inner bowl adapted to be supported on the rim portion of the outer bowl and also having a rim portion, of a lter head having a rim portion detachably secured tothe rim portion of the inner bowl and also having a spider portion within the rim portion which together define enlarged segmental-shaped lter openings between the substantially radial spokes thereof, a sheet of filtering material covering said filter openings and clamped about its marginal edge portion between the rim portion of the lter lhead and the rim portion of the inner bowl, and

an air inspirator nozzle carried on the central portion' of said spider and projecting therefrom through an opening in the sheet of filtering material into the inner bowl to a predetermined level therein and having a restricted air inlet orifice provided in the inner end thereof.

4. A combination as set forth in claim 3, wherethereof covering the enlarged segmental-shaped openings left between the spokes of. the spider portion and said annular rim, and an elongated air inspirator nozzle projecting from the central portion of said spider portion on the inner side thereof and adapted to extend through a hole provided therefor in the sheet of filtering material, said nozzle having a longitudinal hole provided therein extending from theA inner 1 end thereof to the outer side of the filter head.

7. As an article of manufacture, a filter head for a coffee brewing container comprising an annular rim for application to the container and a spider portion within said rim adapted to support a sheet of filtering material on the inner side thereof covering the enlarged segmental-shaped openings left between the spokes of the spider portion and said annular rim, and an elongated air inspirator nozzle projecting from the central portion of said spider portion on the inner side thereof and adapted to extend through a hole provided therefor in the sheet of filtering material, said nozzle having a longitudinal hole provided therein extending from the inner end thereof to the outer side of the Vfilter head, the

spider portion having the spokes thereof inclined inwardly with respect to the plane of the filter head so as' to offset the central portion thereof and correspondingly elevate the nozzle with relation to the rest of the filter head.

8. As an article of manufacture, a filter head for a coffee brewing container comprising an annular rim for application to the container and a spider portion within said rim adapted to support a sheet of filtering material on the inner side thereof covering the enlarged segmental-shaped openings left between the spokes of the. spider portion and said annular rim, the central portion of said spider portion having a circular opening provided therein, and an elongated tapered air inspirator nozzle adapted to be mounted in said opening, said nozzle being formed from a single piece of sheet metal, the enlarged end being open in the lter headhas longitudinal outwardly projecting flangesprovided on the edges of the spokes of the spider portion thereof.

5. A combination as set forth in claim 3, wherein the lter head is attachable to and detachable from the rim portion of the inner bowl by rotary movement, and wherein said filter head has longitudinal outwardly projecting flanges pro-I vided on the edges of the spokes 4of the spider portion thereof, substantially as and for the purpose described.

6. As an article of manufacture, a filter head for a coffee brewing container comprising an annular rim for application to the container and a spider portion within said rim adapted to support a sheet of filtering material on the inner'side and tting in said opening and the other end having a restricted orice provided therein of small diameter in relation to the diameter of the other end of the nozzle.

9. As an article of manufacture, a filter head I for a coffee brewing container comprising an annula'r rim for application to the container and a spider portion within said rim adapted to support a sheet of filtering material on the inner lside thereof.' covering the enlarged segmental-- shaped openings left between the spokes of thespider portion and said annular rim, the central portion of said spider portion having a circular opening provided therein, andan elongated tapered `air inspirator nozzle adapted to be mounted ,in said opening, said nozzle being formed from a single piece of sheet metal, the enlarged end being open and fitting in said opening and the other end having a restricted orifice provided therein of small diameter in relation to the diameter of the other end of the nozzle. said spider portion being formed from sheet metal and having the spokes thereof bent inwardly in relation to th'e plane of the filter head to offset the central portion of the spider portion and accordingly elevate the'nozzle relative to the plane of the lter head.

' HENRY F. KORS. 

